The telephone has become a nearly universal appliance in modern homes and business. While other communications media such as the Internet and satellite and radio communications have advanced, the telephone remains the most popular instrument for communication today. Unfortunately, telephone technology has not been substantially enhanced since its introduction. Telephone connections continue to use analog electrical signal transmission over twisted-pair wires, between individual telephone terminals. While substantial advancements have been made in the transmission of telephone signals, including the use of sophisticated digital switching, digital compression and decompression and digital transmission, telephone terminals remain analog devices connected to standard analog POTS telephone lines. Meanwhile, other communications media, such as the Internet, radio and satellite have evolved utilizing digital technology, which substantially enhances the flexibility of those communication systems, while also improving the quality of transmission.
Recently, with the promulgation of the voice over IP protocol H.323 (VoIP), and the emergence of H.323 compatible software such as “NetMeeting”, digital Internet telephony has become increasingly popular. Digital Internet telephony is accomplished by established a VoIP connection via an existing Internet connection, using the H.245 call management protocol; and then initiating an exchange of information between terminals compatible with the H.323 communication standard.
VoIP terminals typically are computer systems having Internet connections available for established H.323 communication. However, more recently, stand alone VoIP telephone sets have been developed, which are attachable to an Internet connection. Furthermore, hand sets are available for use with computer systems to facilitate the use of the computer system and its Internet connection to perform VoIP telephony. Using these devices, VoIP telephony has become increasingly popular. This popularity is in no small part due to the lack of communication surcharges on traffic passed over the Internet, as compared to the toll based charges for standard telephone service performed via local area telephone and long distance telephone carriers.
A difficulty with VoIP telephony is the need to provide standard POTS telephone connectivity to environments in which digital telephones are in use. A VoIP telephone is not readily configurable to operate as a standard analog telephone, to send and receive calls using POTS telephone standards. Although VoIP telephony is expected to become widely used as a method for telephone communication, it will be necessary for VoIP telephony to coexist with preexisting POTS telephony systems for a substantial period of time to come. Therefore, to convert completely to VoIP telephony, it is necessary to adapt VoIP telephones to operate properly utilizing standard POTS telephone service.
The most popular environment in which VoIP telephony has been used, is large corporate campuses or other substantial installations. In these environments, VoIP telephony may be used within the campus, and communications to outside VoIP or POTS telephone devices can be managed through a central point for the entire installation. VoIP/POTS interfacing and management requires the use of specialized hardware devices known as a voice gateway and call manager.
A voice gateway (also known as a media gateway) is a specialized telephone hardware device including analog to digital and digital to analog conversion systems, that convert an analog POTS telephone line to be connected to one of a number of Internet VoIP telephone sets, so that outbound calls may be originated from a VoIP telephone set and terminated via the publicly switched telephone network, and inbound calls from the publicly switched telephone network can be delivered as VoIP calls to an appropriate telephone. A voice gateway thus permits VoIP telephones to send and receive POTS analog telephone calls. Furthermore, a voice gateway may be used to permit POTS analog telephones to send and receive VoIP Internet telephone calls using the same hardware of the voice gateway. Thus, a voice gateway is installed at a corporate campus or other substantial installation, to permit use of VoIP telephones and legacy POTS telephone sets throughout the installation, with the voice gateway providing interface between the publicly switched telephone network, an Internet connection, and each of the telephones in the corporate campus.
A voice gateway is typically installed along with a call manager (also known as a call agent or media gateway controller) which is responsible for managing the activities of the voice gateway. The call manager includes routing tables identifying the manner in which incoming and outgoing POTS analog and VoIP digital telephone calls should be routed. The call manager utilizes these routing tables to instruct the voice gateway to perform appropriate actions to connect telephone calls to their desired destinations.
The use of voice over IP or VoIP telephony has been limited thus far to corporate campuses and other large installations, for the reason a voice gateway and a call manager are complex and expensive hardware devices. The expense of these devices can only be justified when the potential cost savings from the use of VoIP telephony, will exceed the expense of the voice gateway and call manager. Normally this is possible with large installations where the voice gateway and call manager can be shared by a large number of telephone systems that are under common ownership.
Recently, a number of services have been introduced for the purpose of facilitating individual or small corporate use of VoIP telephony. For example, a service known as DialPad has been established for use by users with computer systems capable of VoIP telephony. According to the DialPad system, a user having an independent Internet connection connects to the DialPad Internet site and delivers a VoIP address or standard analog POTS telephone number to the DialPad server. The DialPad server is connected to both a voice gateway and a call manager, in turn connected to the Internet backbone and to the publicly switched telephone network at one or a number of local areas. The server is capable of delivering a VoIP telephone call to a VoIP telephone recipient via Internet connections and is also able to utilize the voice gateway to translate a VoIP telephone connection from VoIP to standard POTS telephone service for delivery to a standard POTS telephone number. DialPad thus permits a individual or small business user to perform VoIP telephony and POTS telephony over a single Internet connection, however such a user may not receive telephone connections, but may only originate.
A second service, provided to cellular telephone users by Ericsson, is known as Phone Doubler. This service will deliver telephone calls received at a standard POTS telephone number to a VoIP telephone set, provided that VoIP set is currently connected through an ISP and Internet connection. Thus, this service permits inbound POTS analog telephone connections to be routed to a VoIP telephone on an individual basis. However, this service does not permit outbound telephone communication.
A third service of this kind is known as Pagoo.com. In this service, a subscriber obtains a standard POTS telephone number which is owned by Pagoo and is terminated at Pagoo's telephone server. An inbound dialing party connects to Pagoo's server and provides a three digit extension identifying a specific subscriber. This three digit extension is used to route the inbound telephone connection to either a VoIP connection at a computer or a standard analog POTS connection at a subscriber-specified telephone number. To maintain connectivity using the Pagoo system, a subscriber must log in to the server and register a telephone number or computer Internet address before telephone calls may be received. A dedicated VoIP telephone may not be used with the Pagoo system for the reason that it cannot be logged into the server. Furthermore, the Pagoo system does not support outbound telephony, but only inbound telephony using a Pagoo telephone number and a three digit extension.
It can be seen by the foregoing, that the Internet telephony options available to small business and residential users, are substantially limited. A need therefore exists for a methodology and system that permits the use of Internet telephony by residences and small business in a manner directly analogous to the current use of analog POTS telephone service, including inbound and outbound service, multiple inbound and outbound lines, and all other conveniences and features of modern POTS analog telephony.